Search results for "I3"

Mutant HRAS as novel target for MEK and mTOR inhibitors.

2015

HRAS is a frequently mutated oncogene in cancer. However, mutant HRAS as drug target has not been investigated so far. Here, we show that mutant HRAS hyperactivates the RAS and the mTOR pathway in various cancer cell lines including lung, bladder and esophageal cancer. HRAS mutation sensitized toward growth inhibition by the MEK inhibitors AZD6244, MEK162 and PD0325901. Further, we found that MEK inhibitors induce apoptosis in mutant HRAS cell lines but not in cell lines lacking RAS mutations. In addition, knockdown of HRAS by siRNA blocked cell growth in mutant HRAS cell lines. Inhibition of the PI3K pathway alone or in combination with MEK inhibitors did not alter signaling nor had an imp…

A Note on the High Stability of Happiness: The Minimal Effects of a Nuclear Catastrophe on Life Satisfaction

2008

Using life satisfaction as a direct measure of individual utility has become popular in the empirical economic literature. In this context, it is crucial to know what circumstances or changes the measure is sensitive to. Is life satisfaction a volatile concept that is affected by minor changes in life circumstances? Or is it a reliable measure of personal happiness? This paper will analyze the impact of a catastrophe, namely the nuclear catastrophe of Chernobyl, on life satisfaction. I use longitudinal data from the German Socio-Economic Panel Study and especially information collected on a monthly basis which allows the researcher to study calendar effects. The following clear-cut results …

Author response: PTEN negatively regulates the cell lineage progression from NG2+ glial progenitor to oligodendrocyte via mTOR-independent signaling

2018

Amphiregulin activates human hepatic stellate cells and is upregulated in non alcoholic steatohepatitis

2015

AbstractAmphiregulin (AR) involvement in liver fibrogenesis and hepatic stellate cells (HSC) regulation is under study. Non-alcoholic fatty liver disease (NAFLD) and its more severe form non-alcoholic steatohepatitis (NASH) may progress to cirrhosis and hepatocellular cancer (HCC). Our aim was to investigate ex vivo the effect of AR on human primary HSC (hHSC) and verify in vivo the relevance of AR in NAFLD fibrogenesis. hHSC isolated from healthy liver segments were analyzed for expression of AR and its activator, TNF-α converting enzyme (TACE). AR induction of hHSC proliferation and matrix production was estimated in the presence of antagonists. AR involvement in fibrogenesis was also ass…

Acute estradiol protects CA1 neurons from ischemia-induced apoptotic cell death via the PI3K/Akt pathway

2010

Global ischemia arising during cardiac arrest or cardiac surgery causes highly selective, delayed death of hippocampal CA1 neurons. Exogenous estradiol ameliorates global ischemia-induced neuronal death and cognitive impairment in male and female rodents. However, the molecular mechanisms by which a single acute injection of estradiol administered after the ischemic event intervenes in global ischemia-induced apoptotic cell death are unclear. Here we show that acute estradiol acts via the phosphoinositide 3-kinase (PI3K)/protein kinase B (Akt) signaling cascade to protect CA1 neurons in ovariectomized female rats. We demonstrate that global ischemia promotes early activation of glycogen syn…

Control of ovarian steroidogenesis by insulin-like peptides in the blowfly (Phormia regina).

2004

0022–0795/04/0181–147; This study investigated the ability of insulin and of insect insulin-like peptides (ILPs) to stimulate ovarian steroidogenesis in the blowfly Phormia regina. Bovine insulin was active on ovaries isolated in vitro, which showed an age-dependent sensitivity; this peptide progressively stimulated steroidogenesis in ovaries isolated from the third day after adult molt, but not in younger ones, and had maximal activity after the fifth day. This stimulatory effect was observed equally from females reared in the presence or in the absence of males, excluding a regulatory effect of mating. The mode of action of insulin in blowflies did not involve cAMP, but triggered a specif…

Insulin resistance aggravates atherosclerosis by reducing vascular smooth muscle cell survival and increasing CX3CL1/CX3CR1 axis.

2014

Aims Insulin resistance (IR) is a major risk factor for cardiovascular disease and atherosclerosis. Life-threatening acute events are mainly due to rupture of unstable plaques, and the role of vascular smooth muscle cells (VSMCs) in this process in IR, Type 2 diabetes mellitus, and metabolic syndrome (T2DM/MetS) has not been fully addressed. Therefore, the role of VSMC survival in the generation of unstable plaques in T2DM/MetS and the involvement of inflammatory mediators was investigated. Methods and results Defective insulin receptor substrate 2 (IRS2)-mediated signalling produced insulin-resistant VSMCs with reduced survival, migration, and higher apoptosis than control cells. Silencing…

Lipid Activates mTORC1 and mTORC2 in the Absorption of Dietary Triglycerides

2018

Mechanistic target of rapamycin (mTOR) senses amino acids; however, its role in lipid metabolism is less established. Organismal lipid requirements are largely met through dietary intake. How nutrient sensing mechanisms in gut interface with dietary fat remains unclear. Here we reveal fundamental and cooperative roles for mTOR complexes 1 and 2 (mTORC1/2) in absorption of dietary triglycerides. Dietary lipid activates mTORC1/2 signaling in gut. Hyperactivating mTORC1 by deleting Tsc1 is sufficient to promote triglyceride absorption and metabolic disease in high fat-fed mice. Conversely, blocking mTORC1/2 by deleting Raptor or Rictor each decreases triglyceride absorption. Loss of Raptor seq…

The E3 Ubiquitin Ligase MID1 Catalyzes Ubiquitination and Cleavage of Fu

2014

Sonic Hedgehog (SHH)-GLI signalling plays an important role during embryogenesis and in tumorigenesis. The survival and growth of several types of cancer depend on autonomously activated SHH-GLI signalling. A protein complex containing the ubiquitin-ligase MID1 and protein phosphatase 2A (PP2A) regulates the nuclear localization and transcriptional activity of GLI3, a transcriptional effector molecule of SHH, in cancer cell lines with autonomously activated SHH signalling. However, the exact molecular mechanisms that mediate the interaction between MID1 and GLI3 remained unknown. Here, we show that MID1 catalyses the ubiquitination and proteasomal cleavage of the GLI3-regulator Fu. Our data…

FRI0150 Mtor blockade by rapamycin decreases arthritis and spondylitis development and severity in hla-b27 transgenic rats

2018

Career situation of first and presenting author Student for a master or a PhD. Introduction TNF and IL-17A have been demonstrated as key inflammatory cytokines in Spondyloarthritis (SpA), whereas targeting bone remodeling remains an unmet clinical need in SpA. The mammalian target of rapamycin (mTOR) regulates IL-17 expression and osteogenesis and could therefore be a promising therapeutic target in SpA. Objectives To investigate if blockade of mTOR with rapamycin inhibits the pathological processes in inflammation and bone in SpA. Methods Cytokines were measured by ELISA in the supernatant from SpA patient PBMCs stimulated with anti-CD3/CD28, with various concentrations of rapamycin. SpA F…